How Chris Hemsworth became Thor over Liam

It launched his Hollywood career but Chris Hemsworth could have missed out on the role of Thor to his younger brother Liam.

And now Sir Kenneth Branagh, who directed the 34-year-old in the first movie in the franchise back in 2011, has revealed why he opted for the older Hemsworth over his young bro.

"He had the thing, he had that IT factor that was just perfect for this part. Liam did a wonderful job, as did the other actors in the screen test, but this one had Chris Hemsworth's name on it," the director told The Project.

"I couldn't be more proud at what he's done with the role and what he's doing with his career."

Kenneth went on to praise the Australian brothers, saying he couldn't help but think they were "well brought up young men" during the audition process.

"We screen tested five people, and the two people that hung their clothes back up on the costume rail were the Hemsworth brothers. Very well brought up young men, I would say," he added.

• Chris' biceps have 'mind of their own'

• WATCH: Chris Hemsworth is shirtless in new Thor trailer

And while we may have never seen Liam strip off as the hunky Norse God, father-of-three Chris has revealed he didn't want to show off his insanely toned bod in the latest upcoming Marvel installment Thor: Ragnarok.

"Ken Branagh came up to me on the first film and said, 'Oh look, I've got this shirt off scene, how do you feel'," Chris recently explained to USA Today.

"I was like, 'Oh man, I've been working out for eight months; I'm ready, let's go.' And this time around, there wasn't one in the script, which I was really happy about, and then [director] Taika [Waititi] said, 'No, I think we need a shirt off scene.' I was like, 'Ugh, no we've done that. Don't make me do it again!'"

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